BiQuad lowpass filter problem

[DigitalPilgrim]

I have problem with BiQuad lowpass filter.

When I have filter in class for example

class Something
{
public:
     Something();
     q::lowpass filter1;
     q::lowpass filter2;
     void process(float *in, float *out);
}
Something::Something() : filter1(1500.0, 44000), filter2(800.0, 44000, 2.5) {}

it is working as expected, but under same code, when I add another filter in process, filter is not working

void process(float * in, float *out)
{
    // filter created here are not working, they output is not audible
     auto frL = q::lowpass( q::frequency(1500.0), 44000 ); 
     auto frR = q::lowpass{ q::frequency(900.0), (uint32_t)m_sampleRate };

     float L = frL(in[0]); // not audible
     float R = frR(in[1]); // not audible
     L = filter1(in[0]); // working
     R = filter2(in[1]); // working
}

[djowel]

The filter objects should not be instantiated inside process. Make them member variables. The filters are stateful. Your first code is correct. They should all be a class members.

[djowel]

BTW, I suggest using c++ literals. E.g. filter1(1500.0_Hz, 44000)

[DigitalPilgrim]

Aha, thanks.

BTW, I suggest using c++ literals. E.g. filter1(1500.0_Hz, 44000)

Yes, I know, but I am working on realtime application and want change the filter in realtime.

[djowel]

Aha, thanks.

BTW, I suggest using c++ literals. E.g. filter1(1500.0_Hz, 44000)

Yes, I know, but I am working on realtime application and want change the filter in realtime.

Of course :-)